As part of our continuing effort to understand the structure-function relationships of cell surface molecules involved in the immune response, we have been involved in a number of studies applying the methods of recombinant DNA technology to genes that encode the major histocompatibility antigens of the mouse as well as to those that encode molecules linked to the Mls locus on chromosome 1. In particular, we have focused on: A. Generating in vitro recombinant chimeric class II/class I genes, and analyzing their expression biochemically, structurally, and functionally; B. Generating in vitro deletion mutants of the class I MHC genes H-2Ld and H-2Dd and analyzing their expression biochemically, structurally, and functionally; C. Analyzing the protein products derived from alternatively spliced mRNAs of H-2Ld and H-2Dd deletion mutants; and D. Developing a molecular biological approach to the cloning of genes linked to and/or encoding the Mls locus of the mouse, the only known non-major histocompatibility complex locus controlling a primary T cell proliferative response.